Manufacture of isoparaffins



July 30, 1946. L. SCHMERLING ETAL 2,404,927

MANUFACTURE OF ISOKPARAFFINS Filed Feb. l5, 1943 (wea/e125@ 220)! 5Zozze f Patented July 30, 1946 MAN UFACTURE 0F ISOPARAFFINS LouisSchmerling and Vladimir N. Ipatieif, Riverside, Ill., assignors toUniversal Oil Products Company, Chicago, Ill., a corporation of Dela-Ware Application February 15, 1943, Serial No. 475,963

13 Claims. 1

This invention relates generally to processes for the production ofparaflin hydrocarbons of branched chain structure. It is morespecifically concerned with the manufacture of the isoparafflnhydrocarbon 2,2,3-trimethylbutane, commonly known as triptane.

The art of increasing the branching of parain hydrocarbons has beenrapidly developing due to the fact that the more highly branchedparaiiins have been found tobe more reactive chemically than the normalcompounds and the more highly branched normally liquid parafiins havebeen found to possess high antiknock characteristics alone or inhydrocarbon blends used as fuel in internal combustion engines. Thehighly branched paraffin hydrocarbons have advantages over theirolefinic'counterparts in that they are more susceptible to increases inantiknock rating resulting from the addition of minor amounts oftetraethyl lead, and in their greater stability under storageconditions. The isoparaflins have advantages over aromatic hydrocarbonsof comparable antiknock ratings in that they have much lower freezingpoints so that they have a greater safety factor When used in aviationfuel blends which are exposed to greatly reduced temperatures atconsiderable elevations above the earths surface. The isoparaflins arebetter fuels 'than cycloparaflins on account of their generally higherantiknock value over cycloparaiiinic compounds having equivalent boilingpoints.

A hydrocarbon which has been found to possess unusually high antiknockvalue both alone and in hydrocarbon motor fuel blends is the heptane,2,2,3-trimethylbutane, which is the most highly branched heptane isomer.Antiknock rating of this hydrocarbon is abnormally high and its use inaviation engines has been found to increase the take-olf load and thecruising speed of commercial and military airplanes and, therefore, theproduction of this hydrocarbon in commercial quantities would greatlyenlarge the scope of usefulness of all types of airplanes. In its moreparticular aspect the present process can be applied to the manufactureof this particular hydrocarbon.

Numerous hydrocarbon reactions have been employed to produce highlybranched parainic isomers. afiins have been isomerized in contact withvarious types of catalysts, particularly those of the Friedel-Craftstype' and still more particularly the chloride and bromide of aluminumwhich are usually the most eiiicient of the compounds of The normally ormildly branched parthe Friedel-Crafts group in isomerizing paraiinhydrocarbons. In such reactions better results are obtained in thepresence of minor but critical amounts of added hydrogen halides andWater. In these isomerization reactions, however, limits have beenencountered in the degree of branching which can be obtained Withoutsuffering too great losses in the production of hydrocarbons due toconcomitant decomposition reactions. Thus, as temperatures and times ofcatalytic contact are increased, there is a tendency for decompositionor cracking reactions to increase more rapidly than the trueisomerization so that the overall production of more highly branchedisomers is reduced along with the concurrent production of lower boilingparafiins and higher boiling residual compounds. In view of thesedifliculties, it has thus far been impossible `to go beyond a certaindegree of branching by the use of Friedel-Crafts catalysts. In the caseof heptanes only small yields of triptane as representing the highestbranched heptane have been produced although fairly good yields ofdimethylpentanes have been obtained.

Another type of reaction which has been employed to produce isoparainsof motor fuel boiling range has been the alkylation of isobutane,isopentane, etc. with olefin hydrocarbons in the presence of variouscatalysts including mineral acids and metal halides. Here, also limitshave been found to the degree of branching in the alkylation productsand alkylation reactions have not produced any substantial amounts ofthe 2,2,3-trimethylbutane.

The present process involves a combination of interrelated steps wherebyhighly branched paraffin hydrocarbons such as triptane can be producedfrom low molecular weight olens by a series of reactions.

In one speciiic embodiment the present invention comprises a process forthe formation of highly branched iso-paraflin hydrocarbons whichconsists of the following steps: (l) reaction Yof a mono-olefin with analkyl halide; (2) dehydrohalogenation of the alkyl halide produced instep 1 (3) rehydrohalogenation of the oleinic prodducts from step 2; and(4) substitution of methyl groups for the chlorine atoms in the productsfrom step 3.

While the steps of the process thus enumerated are generally applicableto tertiary alkyl halides and olefins of varying molecular weight andstructure, as starting materials they are typified by the particularseries of reactions which can be used for the manufacture of triptane.

The steps in the manufacture of this compound according to the presentprocess are given in the equations and descriptive material whichfollows:

(Step l) CH3 (IH: H Tl Tertiary butyl i-chloro-2,2-dimethylbutanechloride The above reaction may be conveniently brought about in thepresence of such Friedel- Crafts type catalysts as ferrie chloride, andbismuth chloride as representing the moderately active members of thisgroup. To effect the above reaction in the presence of bismuth chloride,temperatures of from about 50 to about 125 C. are suitable and in thepresence of such alternatively utilizable catalysts as ferrie chlorideor zirconium chloride, temperatures of from about to about 50 C. areadequate. Reactions of the above character between tertiary alkylhalides and olefins may be further accelerated by the presence of smallamounts of peroxides such as, for example, benzoyl peroxide, ascaridole,etc. Minor amounts of hydrogen halides also have a beneiicial effect.

The second step of the process as applied to the manufacture of triptaneinvolves the dehydrohalogenation of the primary hexyl chloride and thereaction involved is shown by the following equation in which thecompounds are represented structurally:

Ethylene In the above equation it is indicated that equal molecularamounts of the two possible dimethylbutenes are produced from twomolecules of the chloro compound. The production of exactly molecularproportions, however, does not take place but they will be formed invarying proportions depending upon the exact conditions of operationemployed.

The dehydrohalogenation step may be brought about by contacting thealkyl halide with various alkaline reagents among which may be mentionedalkali metal hydroxides, alkaline earth metal oxides such as lime andmagnesia and the commonly used commercial reagent known as soda lime. bebrought about at varying temperatures depending upon the reagentemployed for the reaction. G-ood yields of the olens are obtainable withgranular soda lime at temperatures of from about 300 to about 450 C. andthe same range of temperature may be used if the alkali metal hydroxidesor alkaline earth metal oxides are employed. When temperatures muchlower than 200 C. are used, the reaction of dehydrohalogenation is slowand the rate is usually below that necessary for making the processpractical. Another method of dehydrohalogenation for the production ofolens consists in heating the alkyl halides with water or aqueoussolutions of acids, bases or salts at temperatures of from about 200 toabout 250 C. and under relatively high pressures, due to the comb-inedvapor pressure of the aqueous solution and the olefin. These pressuresare commonly of the order of 200 to 250 pounds per square inch at atemperature of about 200 C.

The dehydrohalogenation reactions may Still another method ofdehydrohalogenation consists in contacting the alkyl halides withsilica, clays or alumina, and particularly with alumina impregnated withalkaline earth metal halides, at temperatures of from about 200 to about450 C. This method has the advantage that the products contain hydrogenhalide in necessary amount for the next step of the process, namely thereaddition of hydrogen halide to the olefin. In such a case partialre-addition may occur spontaneously before the reaction productrecovered, and, the product from 4chloro2,2diinethyl-butane may consistof a mixture of hydrogen chloride, 2,3-dimethylbutenes and 2-chloro2",3dimethyl-butane. Thus, the original primary chloride has in effect beenisomerized to the desired tertiary alkyl chloride in one step.

It is to be noted that the oien formed as a .result of thedehydrohalogenation step correspend to a shift in the carbon atomstructure, the methyl groups now appearing in the 2,3-position whilethey were in the 2,2-position in the alkyl halide. Therefore, in thenext step of the process, involving the re-addition of hydrogenchloride, the chlorine appears in the Z-position, the hydrogen chloridehaving added according to Markownikoifs rule in which the halogen addsto a carbon atom and the hydrogen to (end carbon only in2,3-dimethylbutene-1) the other carbon atom of the doubly bonded pair.rIhe next step of the process, therefore, is represented by thefollowing equation which shows the formation of the hexyl halide,2,3-dimethyl-2-chloro-butane from either olen:

In the above step hydrogen halide may be added at ordinary temperatures,practical reaction rates having been observed at temperatures of fromabout to about +50 C. Metal halide catalysts are sometimes used. In theoperation of the successive steps of dehydrohalogenation andrehydrohalogenation the desired change iu structure of the chlorobutanemay be brought about in successive zones in a reactor wherein the rstzone contains granular dehydrohalogenating material such as alumina andis maintained at the optimum temperature for effecting the reaction andthe second zone is cooled to a temperature corresponding to there-addition of the hydrogen halide which was evolved in the rst zone.

In the nal step of the process the chlorine atom in the 2-position isreplaced by a methyl group and in bringing about this substitution oneof the more eifective reagents is Zinc dimethyl Which reacts accordingto the following equation:

vent such as toluene or a paraflin hydrocarbon and then to slowly add asimilar solution of the hexyl chloride at a temperature of the order of5 C. which is below the temperature at which rapid reaction occurs. Thesolution is then warmed to a temperature within a range of from about 50to about 90 C. and then refluxed for a period of about 2 hours,hydrolyzed by refluxing with water, the aqueous layer separated and thetriptane distilled from the hydrocarbon solvent after which it may begiven alight treatment with caustic soda to remove chlorine and otherreaction products.

Alternatively with the use of zinc dimethyl for replacing chlorine withmethyl groups in the final step of the process this reaction may bebrought about by the use of methyl metal halides in dilute ethersolutions according to the Grignard synthesis.

In such cases reactions between the alkyl chloride and the Grignard typereagents such as for example methyl magnesium chloride are brought aboutin relatively dilute ether solutions such as ethyl ether, andalternatively analogous compounds of aluminum, zinc or tin may beemployed.

' Thus alternative methyl magnesium chloride may be formed by addingmagnesium to an ether solution of methyl chloride and the reactionbrought about by adding the hexyl chloride to the ether solution. As afurther alternative the solution in ether of the '2-chloro-2,3dimethylbutane may be treated with finely divided metallic magnesium until thecompound 2,3-dimethyl butyl-2-magnesium chloride is formed and thiscompound is then reacted with methyl chloride or methyl sulfatepreferably at room temperatures or slightly below room temperature.

After the final step of the process has been completed the products arefractionated to separate the desired triptane and the solvents which mayhave been employed are re-used and the magnesium recovered from themagnesium chloride by any desired series of steps.

The description of the process in the preceding paragraphs has beengiven in connection with the manufacture of triptane as one application,but the process is broadly applicable to the formation of highlybranched isoparafiln hydrocarbons of higher molecular weight thantriptane by using as starting materials alkyl halides of highermolecular weight than butyl halides and higher molecular weight homologsof ethylene. Furthermore, in the final step wherein the chlorine in thechloroalkane is substituted by alkyl groups, these groups may be ofhigher molecular weight than the methyl groups which are used for theformation of triptane. When different compounds of analogousconstitution are used in the successive steps of the process there willnecessarily be changes in the optimum conditions in each step, althoughthe general procedures will be substantially the same as those describedin connection with the manufacture of triptane.

According to this invention, our process for producing parafnichydrocarbons of highly branched chain structures is illustrated by thenow-sheet given in the attached diagrammatic drawing. For the sake ofsimplicity, the following description of this flow-sheet is given toillustrate the process for producing triptane although other highlybranched paraflins may be produced also by the combination ofcooperative steps utilized in our process.

Referring to the drawing, ethylene is introduced through line I in whichthis gaseous olefin is commingled with tertiary butyl chlorideintroduced through line 2. The mixture of ethylene and tertiary butylchloride is then directed from line I to condensation zone 3 preferablycontaining a catalyst of the Friedel-Crafts type in order to condensetertiary butyl chloride and ethylene to form 4-chloro-2,2dimethylbutane.As hereinbefore set forth, this condensation reaction is carried out ata temperature of from about 50 to about C. in the presence of bismuthchloride, but different temperatures are generally employed whenutilizing ferric chloride, aluminum chloride, aluminum bromide, etc. Thereaction mixture from condensation zone 3 is conducted through line 4 toseparation zone 5 in which unconverted ethylene and tertiary butylchloride are separated from the higher boiling condensation product,hereinbefore referred to as 4-chloro-2,2di methylbutane. The unconvertedethylene and tertiary butyl chloride are recycled through line 6 andline I to condensation zone 3.

In the second step of the process as applied to the manufacture oftriptane, the 4-chloro-2,2di methylbutane is directed from separationzone 5 through line 'I to dehydrohalogenation zone 8 preferablycontaining a dehydrohalogenation catalyst which promotes the splittingof hydrogen chloride from said 4-chloro-2,2-dimethylbutane and resultsin the formation of a mixture of 2,3- dimethylbutene-l and2,3-dimethylbutene-2. Dehydrohalogenation may also be carried out in thepresence of various alkaline reagents but in these cases the hydrogenchloride combines chemically with the alkaline reagent and is notreadily available for further use in the process. Such further use ofhydrogen chloride may be made when a dehydrohalogenation catalyst isutilized.

The reaction mixture from dehydrohalogenation zone 8 is directedtherefrom through line 9 and may be conducted to separation zone I0 orpassed through line II to rehydrohaiogenation zone I2. In the processfor producing triptane, it is generally not necessary to utilizeseparation zone I0 as the entire reaction mixture produced indehydrohalogenation zone 8 generally has the proper proportions ofdimethylbutenes and hydrogen chloride needed for reaction inrehydrohalogenation zone I2 in which hydrogen chloride adds to the2-positior1 of each of the 2 isomeric 2,3- dimethylbutenes forming2,3-dimethyl-2-chlorobutane.v

Also if the dehydrohalogenation reaction is not complete in zone 8, theresultant mixture of hydrogen chloride, 2,3-dimethylbutene-1 and -2 andunconverted 4chloro-2,2dimethylbutane is directed to separation zone I0.Hydrogen chloride is conducted from separation zone IU through lines I3and I5 to line I4, the latter being also employed for conductingr themixture of 2,3-dimethylbutene-1 and -2 to rehydrohalogenation zone I2.If necessary, hydrogen chloride from an outside source may also be addedthrough line I5. Unconverted 4-chloro-2,2dimethylbutane which isseparated from lower boiling materials in separation zone II! may bewithdrawn therefrom through line I6 and thence may be recycled to zone 8by means not illustrated in the diagrammatic drawing.

The reaction mixture obtained in rehydrohalogenation Zone I2 is directedthrough line II to separation zone I8 in which 2,3-dimethyl-2-chlorobutane is separated from any excess of hydrogen chloride, or fromsmall amounts of byproducts. The purified 2,3-dimethyl-2-chlorobutane isdirected from separation zone I8 through line I9 and the hydrogenchloride and/or byproducts are Withdrawn through line to waste orstorage not indicated in the diagrammatic drawing.

In the final step 0i the process, the 2,3-dimethyl-Z-chlorobutane iscommingled in line I9 with a methylating agent such as zinc dimethyladded thereto through line 2| and the resultant commingled mixture isthen conducted to methylation zone 22 in which the chlorine atom of the2,3-dimethyl-2-chlorobutane is replaced by a methyl group to formtriptane. As hereinabove set forth, this replacement of a chlorine atomby a methyl group may also be carried out by utilizing a Grignard typereagent such as methyl magnesium chloride. The reaction mixture soformed in methylation zone 22 is Withdrawn therefrom through line 23 toseparation Zone 24 in which triptane is separated from the reactionmixture. Triptane is withdrawn from separation zone 24 through line 25to storage. The other constituents of the reaction mixture aredischarged from separation Zone 24 through line 26.

When the process of our invention is employed for producing a highlybranched paraiiin hydrocarbon other than triptane, suitable changes aremade in the different steps of the process by employing an appropriatealkyl halide and a suitable olefin is starting materials. The essentialfeature of this process for producing highly branched chain paraiiinhydrocarbons comprises the series of cooperative steps involvingcondensation of an alkyl halide and an olefin, dehydrohalogenation ofthe resultant condensation product, rehydrohalogenation of the olensformed by the dehymay be necessary to discard some of the olefinicisomers from Zone I0 through line l5 and to direct a chosen olenichydrocarbon through line I4 to rehydrohalogenation zone l2. In the abovedescribed process for producing triptane, the 2 olens formed by thedehydrohalogenation reaction were of such structures that they yieldedthe same alkyl halide when rehydrohalogenated and thus the use ofseparation zone I0 was optional.

The following example is given to illustrate the character of resultsobtainable in the practical operation of the process, although it is notintended that the specific data given should unduly circumscribe theproper scope of the invention.

Tertiary butyl chloride is reacted with ethylene in the presence ofbismuth chloride, the two compounds being contacted in approximatelyequimolecular proportions. The temperature employed is 60 C. and it isfound that 4-chloro-2,2- dimethyl butane is produced in 75 per cent ofthe theoretical yield.

The 4-chloro-alkane is then vaporized and passed over granular aluminaat a temperature of 325 C. and atmospheric pressure and the hydrogenhalide and olens produced are re-combined at atmospheric temperature toform the 2-chloro 2,3-dimethyl butane in 90 per cent theoretical yield.The isomerized hexyl chloride is separated by fractional distillationfrom the other reaction products.

To produce the desired triptane a solution of the 2chloro-2,3dimethy1butane in toluene is slowly added to a toluene solution of zinc dimethylat a temperature of 5 C. until there is a slight molal excess of methylgroups in relation to the chlorine atoms present in the heXyl chloride.The toluene solution of the two reactants is then maintained at atemperature of C. for two hours under a reflux condenser, after whichthe solution is cooled and reliuxed with an equal volume of water toeffect hydrolysis and solution of the zinc salts.

The hydrocarbon layer from the aqueous treatment is then distilled torecover triptane which boils at 81 C. The overall weight yield oftriptane based on the combined weight of the tertiary butyl chloride andethylene originally reacted is 40 per cent.

We claim as our invention:

l. A process for the manufacture of isoparaiin hydrocarbons whichcomprises reacting an alkyl halide with a mono-olefin to produce ahigher molecular weight alkyl halide, successively dehydrohalogenatingsaid alkyl halide to produce an olefin, rehydrohalogenating said oleiinto produce an isomer of said higher molecular weight alkyl halide andsubstituting a methyl group for the halogen atom in said last-namedalkyl halide.

2. A process for the manufacture of isoparallln hydrocarbons whichcomprises reacting a tertiary alkyl halide with a mono-olen in thepresence of a Friedel-Crafts type catalyst to produce a higher molecularweight alkyl halide, dehydrohalogenating said higher molecular weightalkyl halide in the presence of a catalyst to produce a mixture ofoleiins, reacting said oleilns with a hydrogen halide to produceisomer-ized higher molecular weight alkyl halides, and substitutingmethyl groups for the halogen atoms in said alkyl halides.

3. A process for the manufacture of isoparaiiin hydrocarbons whichcomprises reacting a tertiary alkyl halide with a mono-oleiin in thepresence of a Friedel-Crafts type catalyst at a temperature of fromabout 10 C. to about 125 C. to produce a higher molecular weight alkylhalide, dehydrohalogenating said higher molecular weight alkyl halide inthe presence of a catalyst at a temperature of from about 200 to about450 C. to produce a mixture or oleflns, reacting said olens with ahydrogen halide at a temperature of from about 50 to about |50 C. toproduce isomerized higher molecular weight alkyl halides, andsubstituting methyl groups for the halogen atoms in said alkyl halides.

4. A process for the manufacture of isoparailin hydrocarbons whichcomprises reacting a tertiary alkyl halide with a mono-olefin in thepresence of a Friedel-Crafts type catalyst at a temperature of fromabout 10 C. to about 125 C. to produce a higher molecular weight alkylhalide, dehydrehalogenating said higher molecular weight alkyl halide inthe presence of a catalyst at a temperature of from about 200 to about450 C. to produce a mixture of olens, reacting said olens with ahydrogen halide at a temperature of from about 50 to about +50 C. toproduce isomerized higher molecular weight alkyl halides, andsubstituting methyl gro-ups for the halogen atoms in said alkyl halidesby reaction with a methyl magnesium halide.

5. A process for the manufacture of isoparaiin hydrocarbons whichcomprises reacting a tertiary alkyl halide with a mono-olefin in thepresence of a Friedel-Crafts type catalyst at a temperature of fromabout-10 C. to about 125 C. to produce 9 a higher molecular Weight alkylhalide, dehydrohalogenating said higher molecular Weight alkyl halide inthe presence of a catalyst at a temperature of from about 200 to about450 C. to produce a mixture of oleiins, reacting said oleiins with ahydrogen halide at a temperature of from about -50 to about +50 C. toproduce isomerized higher molecular Weight alkyl halides, andsubstituting methyl groups for the halogen atoms in said alkyl halidesby reaction With zinc dimethyl.

6. A process for the manufacture of 2,2,3-trimethylbutane whichcomprises reacting tertiary butyl chloride With ethylene in the presenceof bismuth chloride at a temperature of from about 50 to about 125 C. toproduce 4-chloro2,2di methyl butane, dehydrohalogenating said 4 chloro2,2-dimethyl butane in the presence of a catalytic agent at atemperature of from about 200 to about 450 C. to produce an olenicmixture comprising essentially 2,3-dimethylbutene-1 and2,3-dimethylbutene-2, reacting said oleiinic mixture with hydrogenchloride to produce 2- chloro-2,3-dimethylbutane and substituting methylgroups for the chloride atoms in said 2- chloro-2,3-dimethylbutane.

7. A process for'the manufacture of 2,2,3-trimethylbutane whichcomprises reacting tertiary butyl chloride with ethylene in the presenceof ferric chloride at a temperature of from about to about +50 C. toproduce 4-chloro-2,2di methyl-butane, dehydrohalogenatin-g said 4-chloro-2,2dimethyl butane in the presence of a catalytic agent at atemperature of from about 200 to about 450 C. to produce an oleilnicmixture comprising essentially 2,3-dimethylbutene-1 and2,3-dimethylbutene-2, reacting said olenic mixture with hydrogenchloride to produce 2-V chloro-2,3dimethylbutane and substituting methylgroups for the chlorine atoms in said 2- chloro-2,3dimethylbutane.

8. A process for the manufacture of 2,2,3-trimethylbutane whichcomprises reacting tertiary butyl chloride with ethylene in the presenceof bismuth chloride at a temperature of from about 50 to about 125 C, toproduce 4-chloro-2,2di methylbutane, dehydrohalogenating said4-chloro-2,2dimethyl butane in the presence of a catalytic agent at atemperature of from about 200 to about 450 C. to produce an olenicmixture comprising essentially 2,3-dimethylbutene-1 and 2,3- r

-10 to about +50 C. to produce @chloro-2,21 dimethylbutane,dehydrohalogenating said 4- chloro-2,2dimethylbutane in the presence ofa catalytic agent at a temperature of from about 200 to about 450 C. toproduce an olenic mixture comprising essentially 2,3-dimethylbutene-land 2,3dimethylbutene-2, reacting said olefin mixture with hydrogenchloride to produce 2- chloro-2,3dimethylbutane and substituting methylgroups for the chlorine atoms in said 2- chloro-2,3-dimethylbutane byreaction with methyl magnesium chloride.

10. A process for the manufacture of 2,2,3- trimethylbutane whichcomprises reacting tertiary butyl chloride with ethylene in the presenceof bismuth chloride at a temperature of from about to about 125 C. toproduce 4-ch1oro- 2,2-dimethylbutane, dehydrohalogenating said4-ch1oro-2,2-dimethylbutane in contact with a catalytic agent at atemperature of from about 200 to about 450 C. to produce an oleiinicmixture comprising essentially 2,3-dimethylbutene-1 and2,3-dimethylbutene-2, reacting said olen mixture with hydrogen chlorideto produce 2 chloro 2,3 dimethylbutane and substituting methyl groupsfor the chlorine atoms in said 2-chloro-2,3-dimethylbutane by reactionwith zinc dimethyl.

11. A process for the manufacture of 2,2,3- trimethylbutane whichcomprises reacting tertiary butyl chloride with ethylene in the presenceof ferric chloride at a temperature of from about -10 to about +50 C. toproduce 4chloro2,2 dmethylbutane, dehydrohalogenating said 4-chloro-2,2-dimethylbutane in contact with an alkaline catalytic agent ata temperature of from about 200 to about 450 C. to produce an olenicmixture comprising essentially 2,3-dimethylbutene-l and2,3-dimethybutene-2, reacting said oleiin mixture with hydrogen chlorideto produce 2-chloro-2,3-dimethylbutane and substituting methyl groupsfor the chlorine atoms in said 2chloro2,3dimethylbutane by reaction withzinc dimethyl.

12. A process for the manufacture of a 2- chloro-2,3dmethyl alkane whichcomprises subjecting a 4chloro2,2dimethy1 alkane to contact with adehydrohalogenating catalyst to produce olens therefrom and subsequentlyreacting said olens with hydrogen chloride.

13. A process for the manufacture of 2-chloro- 2dirnethyl butane whichcomprises subjecting a 4-chloro2,2dimethyl butane to contact with adehydrohalogenating catalyst to produce oleflns therefrom andsubsequently reacting said oleflns with hydrogen chloride.

LOUIS SCHMERLING. VLADIMIR N. IPATIEFF.

